// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_TREES_SCROLL_NODE_H_
#define CC_TREES_SCROLL_NODE_H_

#include "cc/base/cc_export.h"
#include "cc/output/filter_operations.h"
#include "ui/gfx/geometry/size.h"

namespace base {
namespace trace_event {
    class TracedValue;
} // namespace trace_event
} // namespace base

namespace cc {

struct CC_EXPORT ScrollNode {
    ScrollNode();
    ScrollNode(const ScrollNode& other);

    // The node index of this node in the scroll tree node vector.
    int id;
    // The node index of the parent node in the scroll tree node vector.
    int parent_id;

    // The layer id that corresponds to the layer contents that are scrolled.
    // Unlike |id|, this id is stable across frames that don't change the
    // composited layer list.
    int owning_layer_id;

    // This is used for subtrees that should not be scrolled independently. For
    // example, when there is a layer that is not scrollable itself but is inside
    // a scrolling layer.
    bool scrollable;

    uint32_t main_thread_scrolling_reasons;
    bool contains_non_fast_scrollable_region;

    // Size of the clipped area, not including non-overlay scrollbars. Overlay
    // scrollbars do not affect the clipped area.
    gfx::Size scroll_clip_layer_bounds;

    // Bounds of the overflow scrolling area.
    gfx::Size bounds;

    bool max_scroll_offset_affected_by_page_scale;
    bool is_inner_viewport_scroll_layer;
    bool is_outer_viewport_scroll_layer;

    // This offset is used when |scrollable| is false and there isn't a transform
    // node already present that covers this offset.
    gfx::Vector2dF offset_to_transform_parent;

    bool should_flatten;
    bool user_scrollable_horizontal;
    bool user_scrollable_vertical;
    ElementId element_id;
    int transform_id;

    bool operator==(const ScrollNode& other) const;
    void AsValueInto(base::trace_event::TracedValue* value) const;
};

} // namespace cc

#endif // CC_TREES_SCROLL_NODE_H_
